Life HistoryRed turnip beetles overwinter as eggs in the soil and hatch in late April to early May, shortly after the snow has melted and usually before canola is planted. Adults emerge in early June and feed for 2-3 weeks. At the end of June, adults enter the soil for a one-month resting period. They reappear in July and August and disperse to new Canola fields. The later beetles scatter throughout the fields and are often found mating near the tops of maturing plants. Adults may be seen until October. Only one generation is produced per year.Host and DamageThe red turnip beetle is commonly found in the Aspen parkland region of Alberta and the Peace River regions of both B.C. and Alberta. Crop injury in canola or mustard fields usually occurs along field margins when beetles move in from adjacent fields that had cruciferous plants in the previous year, after volunteer plants are consumed. Adult beetles normally walk to the new food source. Invading beetles are usually concentrated in a moving front only a few feet to meters wide. Adult beetles may damage the seedpods of mature plants. In canola, this damage may cause premature shelling in the swath and loss of crop.ControlCrop rotation reduces the buildup of beetles in a field. If damage or large numbers of red turnip beetles are observed at the edge of a crop field, the extent of beetle feeding into the field should be determined. Even if there are large enough numbers of beetles to do damage, adequate control can usually be obtained by a single pass of an insecticide spray along the affected side of the field.
For more information, contact:
Return to Pest Management Home Return to Grain Factsheets
|
![]() ![]() ![]() ![]() ![]() |